const jokeEl = document.getElementById('joke');
const jokeBtn = document.getElementById('joke-btn');

const xhr = new XMLHttpRequest();
xhr.open('GET', 'https://api.chucknorris.io/jokes/random1');
xhr.onreadystatechange = function () {
    if (this.readyState === 4) {
        if (this.status === 200) {
            const joke = JSON.parse(this.responseText).value;
            jokeEl.innerHTML = joke;
        } else {
            jokeEl.innerHTML = '出现错误，不好笑。';
        }
    }
};
xhr.send();

jokeBtn.addEventListener('click', generateJoke);
document.addEventListener('DOMContentLoaded', generateJoke);